Calculating device



g- 7, 1951 E. GRUNDLEHNER I 2,563,110

' CALCULATING DEVICE Filed Aug. 18, 194'? 4 Sheets-Sheet l IN VEN TOR. ERNEST GRLNDLEHNER ATTORNEY 1951 E. GRUNDLEHNER 2,563,110

CALCULATING DEVICE Filed Aug. 18, 1947 4 Sheets-Sheet 2 I git-4y 4 v 1013 T 9M1 14- 13 INVENTOR.

ERNEST GRUNDLEHNER ATTOR NEY Aug. 7, 1951 Filed Aug. 18, 194'? E.GRUNDLEHNER CALCULATING DEVICE 4 Sheets-Sheet 3 "2355,21, III-iiT-i-TLINVENTOR. ERNEST GRUNDLEHNE R AT TOR NE Y 7, 1951, E. GRUNDLEHNER2,563,110

CALCULATING DEVICE Filed Aug. 18, 194'? 4 Sheets-Sheet 4 FRACTION 0F mcHINVENTOR. ERNEST GRUNDLEHNER g mmw ATTOR NEY Patented Aug. 7, 1951UNITED STATES PATENT OFFICE CALCULATING DEVICE Ernest Grundlehner,Teaneck, N. J

Application August 18, 1947, Serial No. 769,147

1 Claim. 1

This invention relates to an improvement in devices for adding fractionsof inches, inches and feet to give accurate sums of dimensionmeasurements, and relates more particularly to certain improvements inmy prior United States Patent No. 2,223,612.

The present invention relates more particularly to means for addingfractions of inches and the relation of this means to the means foradding inches to show total number of feet and inches and fractions ofinches remaining, the whole being organized in concentric disc and ringarrangement around a central hub, in such manner that the ring showingthe fractions of an inch has a limited movement in either direction,either for adding or for subtracting, but the disc showing the inchesand feet may be turned a full circle.

The invention also relates to means for quickly resetting the inner feetand inch adding disc, and for quickly distinguishing th areas of thefraction ring for use in adding and for use in subtracting fractions ofan inch.

The invention also relates to the structure of the base and the meansfor mountin the disc and ring in position for concentric movementindependent of each other.

For further comprehension of the invention, and of the objects andadvantages thereof, reference will be had to the following descriptionand accompanying drawing, and to the appended claim in which the variousnovel features of the invention are more particularly set forth.

In the accompanying drawing forming a material part of this disclosure:

Fig. l is a plan view of the improved dimension adding and subtractingdevice. a

Fig. 2 is a, similar view, showing the outer facing sheet or panelremoved.

Fig. 3 is a cross sectional view, taken on line 3--3 of Fig. 1, lookingin the direction of the arrows.

Fig. 4 is a bottom plan view.

Fig. 5 is a view similar to Fig. l, but showing a modification of thepresent invention and with portions thereof broken away to show thespring returning means for the movable disc and ring.

Fig. 6 is a transverse cross section view taken substantially on theline 6-6 of Fig. 5.

Referring to the drawings, which illustrated the practical embodiment ofthe invention, In designates a body or base, which may be constructed ofplastic or other material, cast or molded to provide on the lower side aseries of radial stiffening ribs H, a marginal edge rib l2, and internalring ribs l3 and M which intersect the radial ribs.

On the upper side, the base NJ is formed with a central hub or pivotprojection l5, a circular rib l6 concentric with the hub projection I5,and a bounding circular rib ll, concentric with the rib l6 and the hubl5.

'Around the hub an inner movable disc 18 is disposed, and between theinner rig l6 and the outer rib I! a movable rin I9 is disposed for freemanual turning.

The inner disc 18 is formed with a series of radially disposed edgeslots 20, each of which is open through the outer edge of the disc, andmay be further provided with a series of pin holes 21, each one of theholes 2| being disposed in radial line position with one of the edgeslots 2!), and both the edge slots and the pin holes being equallyspaced apart from each other. The slots 20 and the pin holes 2| formcomplete circles, and thus provide for the complete use of the entiredisc l8 in addition and subtraction.

The ring I 9 is formed with a series of pin holes 22, disposed in asemi-circular row adjacent to the inner edge of the ring and equallyspaced from each other, and a series of edge notches 23, which openthrough the inner edge of the ring, and are disposed in a secondsemi-circular row, the two semi-circular rows forming a single completecircle.

The disc [8 and. the ring it are covered by a face plate 24, which issecured to the base by removable screws 25. This face plate may be madeof plastic or other material, and is formed with an arcuate slot 26 onthe right side thereof, which is disposed in registration with thecircular row of pin holes 2!. of the disc [8, but has a, total lengthwhich is a minor fraction of the circumference of the disc !8 at itsouter edge. The face plate 24 is also formed with another arcuate slot2i on the left side, of similar relative length, which registers withthe row of pin holes 2|, the inner ends of the two arcuate slots beingseparated from each other, and being concentric to the disc IS.

The face plate 24 is further formed with an outer right arcuate slot 28,which is concentric to the ring is, disposed in registration with theinner edge semi-circular row of pin holes 22, and is further formed withan outer left arcuate slot 29, which is disposed in registration withthe row of inner edge slots 23. The two slots 28 and 29 are spaced apartat their adjacent ends.

The slots 26and 28' on the right side of the 3 face plate are used foraddition, and the slots on the left side of the face plate are used forsub-' traction.

The base 10 is provided on its bottom side with a groove 43, which opensat one side of the base, and with a spring 44, which has its outer enddisposed across the groove 33. A stylus 45 is disposed in the grooveunder the spring 44, and when withdrawn may be used for operating thedisc [8 and the outer ring I9, in a step-by-step action.

With the disc l8 at zero and the outer ring at zero, the pin end of thestylus 45 is inserted in one of the right slots. If it is desired. tofirst add inches, say 3 inches and then 6 inches, the disc I8 is shiftedfirst by inserting the stylus pin in the hole opposite 3, in the innerright hand slot 26, andmoving the stylus pin downwardly or toward theoperator, against the end 26' of the slot, when the stylus pin is liftedout of the pin hole and then inserted in the pin hole 2| opposite thenumeral 6 on the slot 26. The stylus pin is then used to swing the disc18 to bring the stylus pin against the end stop 26. This will then showa total of 9 inches through the window 38. If it is then desired to add2 ft. and inches to the total of 9 inches, the disc I8 is advanced 2 ft.by inserting the stylus pin in the pin hole 2i opposite the mark whichis marked 2 ft. or 24 inches, and the disc is swung until the stylus pinengages the end stop 26. Then proceed the same way with 5 inches. Thewindows 37 and 38 will now show a total of 3 ft., 2 inches, or 9 inchesplus 2 ft. 5 inches.

The face plate 24 is further formed with another arcuate slot 30,concentric to the ring 19, which is located outwardly of the slot 29 andconcentric with it. The ring [9 is provided with a stud pin 3|, whichprojects into the slot 30, and forms a limit stop for said ring [9' toengage the ends 36 and 3il 'of the slot 30.

The disc [8 is provided with an outer circular row 32 of small figures,starting from 0, representing zero, and arranged in groups. The firstgroup,

reading from, the left to the right of the zero mark 33, starts with 1and ends with 23. Each, succeeding group of numbers starts with G andends with 11, the 0' mark representing 12. The circular row of smallfigures 32* forms a complete circle, which is concentric to the outeredge of the disc I8. The row of small figures 32 represents inches.Inwardly-of this row'32 there is'an incomplete circular row of figures 33, which represent feet, and this row consists of groups of the samefigure. consists of 12 duplicates of the figure 2. Each succeeding groupconsists of 12 duplicate-figures of the succeeding higher value, as 3,then 4, then 5; and the last group shows 12 duplicates of" the figure 9.The last mark or symbol is the zero mark of 0.

The outer ring I9 is provided with an inner circular row of figures 35,which represents fractions of inches, starting with X and continuing insteps of A to and including Thering I 9 is further provided with anouter circularrow of decimal equivalents 3%, which isdisposedconcentrically of the inner row 35, witheach of the fractions ofthe'row 3-5 lined radially with its decimal equivalent'in'the'row 3G,

The face plate 2 3' is further provided with windows 31' and, 38 for theinch and feet-numbers of the disc- 18, with a; window 39 for thefractions of the outer ring l9, and a window 0 for. the decimalequivalents thereof. The windows 31,

For example, the first group 4 38 and 39 are disposed in a radial line,and the window 40 is oifset.

The face plate 24 is further provided with a circular window 4| disposedconcentric to the disc [8 which i provided with a resetting mark 42,which is visible at all times through the circular window M.

The face plate 24 is provided with a circular row of numbers 26*adjacent to the slot 26, and in consecutive order from 1 to 36,inclusive, located on the outer side of the slot 26, and index marksshowing to 1 ft., 2 ft. and 3 ft. points on the slo't'ZB, on the outerside of the slot 26. The cover plate 24 is also provided with a circularrow of numbers 28, located around the outer edge of the slot 28, andstarting with & and increasing progressively to The slot 26* on the leftside of the face or cover plate 2 5 which also registers with the pinholes 2!, is provided with a circular row of figures 2 6; and with indexmarks showing the points on the slot for the; 1 ft., 2ft. and 3 ft.positions. The left slot 29 in the face plate, which registers with thepin holes 22', is provided with a circular row of numbers 28, showingsteps in fractions of an inch, starting with and ending with %5. Theupper end of the right slot 2% is formed with aradial extension slot28", which terminates in a short arcuate slot 25", disposed inconcentric relation to the pin hole row 2!. The upper end of the slot 28is formed with a radial extension 28, which terminates in a shortarcuate slot 28 which is concentric with the pin holes 2!.

Now if it is desired to subtract 19 inches from this total, the styluspin is inserted in the corresponding left slot 26 and in the pin holeopposite 19 inches, and the disc is is swung downwardly against the endstop 25', thus swinging the disc i8 in the opposite direction andproducing the total of 19 inches in the window 38.

By using the stylus in the outer slot 28, toengage the pin holes 22, onthe right side of the face plate; the outer ring i9 may lic nsed foradding fractions of an inch, in steps of and by using the correspondingslot on the left side of'the face plate, by inserting the stylus pinthrough it into the pin holes 22, the ring 12 may be used for subtracting fractions from those added by right operations.

Whenever a fraction is added, the decimal equivalent of the finalfraction will appear through its window 40, and whenever a fraction issubtractedthe resulting decimal equivalent of thereduced fraction willappear through the window 43 of the face plate.

The radial extension is made to slide the stylus pin from the outer'ringinto the disc along extension slot 28 "'whenever the resultof fractionadding exceed %4" or along extension slot28 when the subtraction passesthe full inch as for instance I A less "A In this case the stylus pin isgoing up and around and down as indicated by the diagram at the centerof the drawing.

The outer ring !9 may be provided with an additional circular row of pinholes, arranged to be concentric with the inner edge of theoutermostslotiifl of theface'plate;

The invention thus provides rotary ,ineans'for addingfractions; ofinches, inches, and feet,v up to the lofootcapacity of the device, thetwo zero marksqindicating one complete revolution and one inch more thanthe highestnumber of9" 1'1.'

7, The invention will be particularly useful. for measuring materialsfor cabinet-andsheet metal work, 'fbrm'achinist' operations, forbuilding and material calculations, and for all work where dimensionsare given or required, accurate results are' of critical importance. andthe avoidance of errors insures against mistakes in ordering and wasteof supplies.

The right group of internal edge slots of the outer ring 19 are printedor presented in white, and the left group of internal edge slots of thisring are printed or colored red, or some other distinguishing orcontrasting color, so that the operator will know when he must move thestylus up, down and back as indicated in the diagram at the center ofthe drawing.

In order to automatically return the disc and the ring to their initialor starting positions, a modified construction is shown in Figs. and 6,wherein a spiral spring 50, of the clock spring type, is nested in acircular recess 5! formed in the base l0, and the inner end of thisspring is secured by the pin 52 to the base, and the outer end of thespring is secured by the pin 53 to the disc I8. A similar spring 54 isnested in the recess 55 of the base [0' beneath the outer ring l9, andits inner end is secured to the base l0 by the pin 56, and its outer endis secured to the ring I9 by the pin 51.

The face plate 24' is formed with an opening 24 disposed in line withthe disc l8, so that a finger may be applied to the disc to hold itagainst reverse movement of the return spring 50, and is provided withanother opening 24' disposed in line with the outer ring [9, so that theouter rin may be held against the action of its return spring 54.

By this construction both the disc and the ring will automaticallyreturn to their initial positions, and the effort required of theoperator is accordingly minimized.

While I have illustrated and described the preferred embodiments of myinvention, it is to be understood that I do not limit myself to theprecise constructions herein disclosed and the right is reserved to allchanges and modifications coming within the scope of the invention asdefined in the appended claim.

Having thus described my invention, what I claim as new, and desire tosecure by United States Letters Patent is:

In a calculating device having a base upon which :a, disc and aconcentric outer ring are turnably mounted on a common plane and eachhaving a normal zero setting, a face plate mounted on the base andcompletely coextensive with and overlying the disc and the outer ringretaininE them in rotative position on the base, a concentric recessformed in the base beneath the disc, a spiral spring within said recessand having one end attached to the base and its other end attached tothe disc for returning the disc to its zero setting after being turnedaway from that setting, a second concentric recess formed in the base tosurround said first recess and beneath the ring, and a spiral springwithin said second recess and having one end attached to the base andits other end attached to the ring for returning the ring to its zerosetting after being turned away from that setting, the face plate beingformed with openings overlying the disc and the ring and through whichones fingertips can be engaged to frictionally bear against the topfaces of the disc and the ring for manually holding the disc and thering against the action of the springs in positions turned away from thezero settings.

ERNEST GRUNDLEHNER,

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 199,289 Hart Jan. 15, 1878819,689 Brewer May 1, 1906 1,129,033 Baur Feb. 16, 1915 1,883,037 SnookOct. 18, 1932 2,237,873 Barok Apr. 8, 1941 FQREIGN PATENTS NumberCountry Date 359,259 France Jan. 15, 1906

